JP2002189452A - Semiconductor integrated circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor integrated circuit (a liquid crystal driving IC) which is readily connected to a display device such as a conventional liquid crystal panel as well as a display devil, whose number of pixels per unit area is increased, without greatly reducing the wiring pitch of a printed circuit board. SOLUTION: The circuit is provided with a storage means 4 which receives data representing an image to be displayed on a display device, stores the data that are made corresponding to a plurality of signal electrodes of the display device and outputs the stored data from a plurality of output terminals, a signal generating means 7 which generates a plurality of signals to be supplied to a plurality of signal electrodes of the display device based on the data being inputted to a plurality of input terminals and outputs the signals from a plurality of the output terminals and a selecting means 6 which selects the data inputted from the plurality of the output terminals of the storage means according to the selected signal inputted from the outside and supplies the signals to a plurality of input terminals of the signal generating means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor integrated circuit (liquid crystal driving IC) for driving a display device such as a liquid crystal panel.
More particularly, the present invention relates to a semiconductor integrated circuit including a random access memory (RAM) for storing display data.

[0002]

2. Description of the Related Art A liquid crystal panel is widely used in a display section of a small device such as a clock or a mobile phone. Furthermore, in recent years, while the amount of information to be displayed has increased, there has been a demand for smaller screens and improved visibility and beauty of the screens. In order to display an image more beautifully and clearly on the screen of a display device such as a liquid crystal panel, the size of each pixel (dot) may be reduced and the number of pixels per unit area may be increased. For that purpose, it is necessary to reduce the interval between the scanning electrodes and the interval between the signal electrodes of the liquid crystal panel.

FIG. 7 shows a circuit board 43 on which a conventional liquid crystal driving IC 41 and a conventional liquid crystal panel 42 are mounted. In FIG. 7, the scanning signal C0 is output from the liquid crystal driving IC 41.
A plurality of terminals for outputting .about.C7 are connected to a plurality of scanning electrodes of the liquid crystal panel 42 via a wiring pattern formed in a U shape on the circuit board 43. Further, a plurality of terminals for outputting the display signals S0 to S15 from the liquid crystal driving IC 41 are connected to a plurality of signal electrodes of the liquid crystal panel 42 via wiring patterns formed linearly on the circuit board 43. .

[0004]

In such a liquid crystal panel, if the interval between the scanning electrodes and the interval between the signal electrodes of the liquid crystal panel are reduced in order to increase the number of pixels per unit area, the pitch of the electrodes on the circuit board side is reduced. Must also be narrow.

However, since a large number of signal electrodes are provided in a liquid crystal panel, if the pitch of the signal electrodes is reduced, the wiring pitch of a wiring pattern connected to the signal electrodes reaches a limit, and the density is further increased. Was difficult. Further, in a circuit board, if the wiring pitch of the wiring pattern is too narrow, there is a problem that mounting accuracy on the board is reduced.

In view of the above, the present invention provides a wiring pitch of a circuit board for both a conventional display device such as a liquid crystal panel and a display device having an increased number of pixels per unit area. It is an object of the present invention to provide a semiconductor integrated circuit (liquid crystal driving IC) that can be connected without being too narrow.
Note that, in the present application, the circuit board refers to a printed circuit board, a flexible board, a transparent insulating board, or the like, which can connect a liquid crystal display panel and mount a liquid crystal driving IC and has electric wiring.

[0007]

In order to solve the above-mentioned problems, a semiconductor integrated circuit according to a first aspect of the present invention is a semiconductor integrated circuit for driving a display device, and displays a signal on a display device. Storage means for inputting data representing an image to be stored and storing data corresponding to a plurality of signal electrodes of the display device, and outputting the stored data from a plurality of output terminals; and a plurality of input terminals. A signal generating unit that generates a plurality of signals to be supplied to a plurality of signal electrodes of the display device based on the data and outputs the signals from a plurality of output terminals; Selecting means for selecting data input from the terminal and supplying the selected data to a plurality of input terminals of the signal generating means.

A semiconductor integrated circuit according to a second aspect of the present invention is a semiconductor integrated circuit for driving a display device, which receives data representing an image to be displayed on the display device and an address signal. Means for storing data in an area specified by the address signal, outputting the stored data from a plurality of output terminals, and storing a plurality of externally input addresses in accordance with an externally input selection signal. A plurality of signals to be supplied to a plurality of signal electrodes of a display device based on data input to a plurality of input terminals from a plurality of output terminals of the storage means; Signal generating means for outputting from a plurality of output terminals.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. The same components are denoted by the same reference numerals, and description thereof will be omitted.

FIGS. 1 and 2 are views showing a state where a semiconductor integrated circuit and a liquid crystal panel according to a first embodiment of the present invention are mounted on a printed circuit board. In the present embodiment, the present invention is applied to a liquid crystal driving IC.

The liquid crystal panel 2 shown in FIG. 1 has a smaller distance between signal electrodes in order to increase the number of pixels per unit area than the conventional liquid crystal panel 22 shown in FIG. For this reason, the signal electrodes to which the display signals S0 to S15 are supplied are sorted up and down in the figure so that adjacent signal electrodes are not overcrowded. With such a terminal arrangement, the wiring pattern can be connected to the liquid crystal panel 2 by staggered wiring, so that the wiring pitch does not become too narrow.

Here, the staggered wiring means that, when a wiring pattern is connected to the terminal of the liquid crystal panel 2, for example, the even-numbered signal lines are from the lower side and the odd-numbered signal lines are from the upper side. Wiring that is performed alternately from left and right. According to the staggered wiring, the wiring pitch on the printed circuit board can be maintained as it is even if the interval between the signal electrodes of the liquid crystal panel 2 is reduced to half. Therefore, the pixel density of the liquid crystal can be improved while maintaining the mounting accuracy.

Liquid crystal drive I for driving liquid crystal panel 2
C1 has a built-in RAM (random access memory) for storing display data. Based on the display data, display signals S0 to S15 to be supplied to each signal electrode of the liquid crystal panel 2 are generated.

In FIG. 1, display signals S0, S2,.
, S14 are inputted from the lower side in the figure, and the display signals S1,
S3,..., S15 are wired so as to be input from the upper side in the figure.

On the other hand, in FIG. 2, all the display signals S
.., S15 are arranged in the same arrangement as the output arrangement of the RAM, and are wired so as to be inputted from the lower side in the figure.

1 and 2, the scanning signal C
0 to C7 are wired so as to be input from the left side in the figure.

However, when the terminals are arranged as shown in FIG. 1, the arrangement of the display signals output based on the display data stored in the RAM of the liquid crystal driving IC 1 and the arrangement of the signal electrodes of the liquid crystal panel 2 are one. Therefore, it is necessary to change the arrangement of the display signals in the liquid crystal driving IC 1. When such control is performed by a CPU (Central Processing Unit), the load on the CPU increases. Therefore, in the present embodiment, in the liquid crystal driving IC 1, the RAM
The output arrangement of the display signals is changed by providing a selection circuit (selector) for the output of.

FIG. 3 is a diagram showing the configuration of the liquid crystal driving IC according to the present embodiment. As shown in FIG. 3, the liquid crystal drive IC inputs display data representing an image to be displayed on a liquid crystal panel, stores the data in correspondence with a plurality of signal electrodes of the liquid crystal panel, and stores the stored display data. Is output from a plurality of output terminals.
The storage area of the display data in the display data RAM 4 is
It is specified by the address control circuit 5.

The selection circuit 6 selects display data input from a plurality of output terminals of the display data RAM 4 according to a selection signal input from the CPU, and supplies the display data to a plurality of input terminals of the signal side driving circuit 7. I do. Signal side drive circuit 7
Generates a plurality of signals to be supplied to a plurality of signal electrodes of the liquid crystal panel based on display data input to a plurality of input terminals, and outputs the signals from a plurality of output terminals.

That is, the selection circuit 6 includes the display data RAM 4
Display data R1 to R15 input from
The positions of the display data are rearranged and output according to the selection signal indicating the staggered wiring or the normal wiring input from U. When the staggered wiring is selected, as shown in FIG. 3, the display data T0, T2,.
5, T13,..., T1.

The signal-side drive circuit 7 converts the display data input from the selection circuit 6 into a drive signal, and converts the display data into a display signal S0,
S2, ..., S14, S15, S13, ..., S1
Is generated and output to the liquid crystal panel. The drive control circuit 8
The read timing of the display data RAM 4 is controlled, and the scan side drive circuit 9 is controlled to supply a scan signal to the liquid crystal panel.

Next, the selection circuit 6 of FIG. 3 will be described in detail. FIG. 4 is a circuit diagram showing a configuration of the selection circuit.
The display data R0 to R1 are transferred from the display data RAM to the selection circuit.
When 5 is input, each display data is input to the circuits 11 to 16 shown in FIG. On the other hand, from the CPU,
The selection signal is input to the circuits 11 to 16. The display data R0 is always output as the display data T0.

Here, when the staggered wiring is selected, as shown in FIG. 4, the circuits 11, 12, 13,.
, 14, 15, and 16, the display data R2, R
, R5, R3, R1 are selected and output as T2, T4, T6,..., T5, T3, T1. On the other hand, when the normal wiring is selected, the circuits 11, 12, 13,.
6, R1, R2, R3,..., R13, R1
4, R15 are selected respectively, and T1, T2, T3,
.., T13, T4, and T15.

Referring again to FIG. 3, the display data selected and rearranged in the selection circuit 6 as described above is:
The signal is converted into a display signal in the signal side drive circuit 7 and output to the liquid crystal panel. At this time, if the display signals are arranged for staggered wiring, when mounting the liquid crystal panel,
By performing the staggered wiring as shown in FIG. 1, display signals are input to the liquid crystal panel in the original order. On the other hand, when the display signals are arranged for normal wiring, the display signals are input to the liquid crystal panel in the original order by performing the normal wiring as shown in FIG.

As described above, according to the present embodiment, in the liquid crystal drive IC, by providing the selection circuit on the output side of the display data RAM, the selection signal from the CPU allows
The arrangement of display signals for staggered wiring and the arrangement of display signals for normal wiring can be switched.

Next, a semiconductor integrated circuit according to a second embodiment of the present invention will be described. FIG. 5 is a diagram illustrating a configuration of a semiconductor integrated circuit (liquid crystal driving IC) according to the present embodiment. In FIG. 5, a selection circuit 10 for selecting the arrangement of display signals output from the liquid crystal driving IC is provided on the address control circuit side of the display data RAM. That is, in the present embodiment, the display data is stored in the display data RAM 4.
At the stage of assigning an address when writing to or reading data from the display data RAM 4, a row of lines for normal wiring or a corresponding address for staggered wiring is assigned according to a selection signal.

FIG. 6 is a circuit diagram showing a configuration of the address control circuit 5 and the selection circuit 10 of FIG. In FIG.
The address for the normal wiring or the address for the staggered wiring is determined by the CPU from the NORMAL line or the CH.
It is determined by a signal input to the IDORI line.

For example, when performing normal wiring, NOR
When a voltage is applied to the MAL line, the line 31 is selected from the lines 31 and 32 connected to the B2 line, and the address 0001 (decimal 1) is selected.
Is assigned. Similarly, of the lines 33 and 34 connected to the line B4, the line 33 is selected, and the address 0010 (decimal 2) is assigned.

When staggered wiring is performed, the CHID
A voltage is applied to the ORI line, the line 32 is selected from the two lines connected to the B2 line, and an address 0010 (decimal 2) is assigned. Similarly, in line B4, line 34 is selected and assigned address 0100 (decimal 4).

By supplying the selected address to the display data RAM in this way, the arrangement of the display signals output from the liquid crystal driving IC can be switched between the normal wiring and the staggered wiring.

[0031]

As described above, according to the present invention, the arrangement of the output display signals can be switched by the selection signal by adding the selection circuit to the liquid crystal driving IC. Accordingly, the normal wiring and the staggered wiring can be selectively used by using the same liquid crystal driving IC without imposing a load on the CPU. Also, by using staggered wiring,
It is also possible to mount a high-density liquid crystal panel without reducing the wiring pitch of the circuit board.

In the above description, a printed circuit board is taken as an example of the circuit board. However, the same effect can be obtained by using another type of flexible board or transparent insulating board.

[Brief description of the drawings]

FIG. 1 is a diagram showing a state where a semiconductor integrated circuit and a liquid crystal panel according to a first embodiment of the present invention are mounted on a printed circuit board.

FIG. 2 is a diagram showing a state where the semiconductor integrated circuit according to the first embodiment of the present invention and a conventional liquid crystal panel are mounted on a printed circuit board.

FIG. 3 is a diagram illustrating a configuration of a semiconductor integrated circuit according to the first embodiment of the present invention.

FIG. 4 is a circuit diagram showing a configuration of a selection circuit of FIG. 3;

FIG. 5 is a diagram illustrating a configuration of a semiconductor integrated circuit according to a second embodiment of the present invention.

FIG. 6 is a circuit diagram showing a configuration of an address control circuit and a selection circuit of FIG. 5;

FIG. 7 is a wiring diagram in which a conventional semiconductor integrated circuit and a conventional liquid crystal panel are mounted on a circuit board.

[Explanation of symbols]

 1, 41 semiconductor integrated circuit (liquid crystal driving IC) 2, 22, 42 liquid crystal panel 3, 23 printed circuit board 43 circuit board 4 display data RAM (random access memory) 5 address control circuit 6, 10 selection circuit 7 signal side driving circuit 8 Drive control circuit 9 Scan side drive circuit 11-16 Circuit 30-34 Wiring line

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H093 NA16 NA47 NC28 NC50 ND20 5C006 BB11 BC02 BC21 BF24 EB05 FA41 FA42 5C080 AA10 BB05 DD22 DD23 DD25 JJ02 JJ03 KK47 KK49 5F038 DF01 DF05 DF16 EZ20

Claims (2)

[Claims] 1. A semiconductor integrated circuit for driving a display device, wherein data representing an image to be displayed on the display device is input and the data is stored in correspondence with a plurality of signal electrodes of the display device. Storing means for outputting stored data from a plurality of output terminals; and generating a plurality of signals to be supplied to a plurality of signal electrodes of the display device based on the data input to the plurality of input terminals. Means for outputting data from a plurality of output terminals of the storage means according to a selection signal inputted from outside, and supplying the selected data to a plurality of input terminals of the signal generation means. A semiconductor integrated circuit comprising: 2. A semiconductor integrated circuit for driving a display device, wherein data representing an image to be displayed on the display device and an address signal are inputted, and the data is stored in an area designated by the address signal. Storing means for outputting stored data from a plurality of output terminals, and selecting means for selecting a plurality of externally input addresses according to a selection signal input from the outside and supplying the selected addresses to the storage means Generating a plurality of signals to be supplied to a plurality of signal electrodes of the display device based on data input from a plurality of output terminals of the storage unit to a plurality of input terminals, and outputting the signals from the plurality of output terminals. And a signal generation unit.